1. Field of the Invention
The present invention relates to a display apparatus. More particularly, the present invention relates to a display apparatus designed with a daisy chain.
2. Description of Related Art
As the optoelectronic technology and semiconductor manufacturing technology have become increasingly mature, flat panel displays are developed rapidly. Among others, LCDs, advantageous in low-voltage operation, no radiation, low weight, and small volume, has gradually replaced conventional CRT displays to become a mainstream display product in recent years.
Generally speaking, a LCD panel is mainly constituted by a substrate, an opposite substrate, and a liquid crystal layer disposed between the above two substrates. FIG. 1 is a top view of a substrate of a conventional LCD panel. The conventional LCD panel is provided with a substrate 110, a FPC (flexible printed circuit) 120, and a PCB (printed circuit board) 130. The substrate 110 has an active region A and a peripheral circuit region B located outside the active region A. Pixel units P are disposed in the active region A, and the first driving circuits 170, an electrode line 112, and conductive portions 114 are disposed in the peripheral circuit region B. The electrode line 112 is disposed surrounding the active region A. The conductive portions 114 are made of a conductive material, for example, a mixture of conductive particles and an adhesive.
The FPC 120 has second driving circuits 171. As shown in FIG. 1, the electrode line 112 is electrically connected to the PCB 130 through the FPC 120, for transmitting a common voltage. Generally speaking, after the assembly of the substrate 110 and an opposite substrate (not shown), a counter electrode on the opposite substrate is electrically connected to the electrode line 112 through the conductive portions 114, such that the common voltage may be transmitted to the counter electrode of the opposite substrate.
According to the technology of the conventional LCD panel, if the electrode line 112 is broken or has defects, the common voltage may not be uniformly transmitted to each point on the counter electrode, thus causing the LCD panel to display an abnormal frame. Moreover, the counter electrode may have an abnormal voltage since the conductive material of the conductive portions 114 is insufficient or many bubbles distribute over the conductive portions 114, and it is hard to find out which one of the conductive portions 114 has problem.